Fiber-reinforced resin materials, or “composite” materials as they are commonly known, have many applications in the aerospace, automotive, and marine fields because of their high strength-to-weight ratios, corrosion resistance, and other unique properties. Conventional composite materials typically include glass, carbon, or polyamide fibers in woven and/or non-woven configurations. The fibers can be pre-impregnated with uncured resin to form fiber plies in a raw material stage. The fiber plies can be manufactured into parts by laminating them on a mold surface. Heat and pressure can be applied to the laminated plies to cure the resin and harden the laminate in the shape of the mold. The heat and pressure can be applied with an autoclave, a heated flat or contoured forming tool, or a combination of methods including the use of a vacuum bag.
Composite parts can be formed in the above manner on both male and female tools. The tools are machined to exacting measurements and must not have their dimensions altered during the repeated laminate fabrication processes, which may include temperature and/or pressure cycling. Ideally, thermal characteristics of the tooling should be comparable to those of the composite parts being fabricated. In this way, substantially identical laminates are formed during laminate production. However, tools, especially tool surfaces can be become damaged, for example, during storage or transport. When a tool is damaged, it must be repaired or replaced. Due to the significant expense required to fabricate precision metallic tooling for laminate production, it is often impractical to maintain duplicate metal tools. As a result, such repair or replacement often adversely affects, and otherwise interrupts or delays, laminate production.
Further, as the structure of composite parts becomes more complex, it becomes more difficult to fabricate precision tools capable of achieving desired tolerances of the composite parts, for example, composite parts with compound contours and undercuts.
Accordingly, there remains a need in the art for composite parts and methods and apparatus for manufacturing these composite parts using resin infusion processes without expensive hard tooling.